Blast furnace hot blast stove



June 27, 1933. R CRHGAN 1,915,880

BLAST FURNACE HOT BLAST STOVE NVENTOR ATTORNEYS Patented June 27, 1933 This invention relates to hot blast stoves for use in preheating air for. blast furnaces. In particular it relates to thattypeof hot blast stove known in the artas a fire/brick 5 stove which comprises substantially an arrangement of fire brick and a backing of other brick within a cylindrical, vertical, airtight, steel tank, the dimensions ofthe steel tank and the arrangement of fire brick withinit varying greatlyaccording tocapacities desired and according to the varying ideas of different designers. The main idea, however, in this type of hot blast stove` is to burn a mixture of air and gas within a certain portion of the .brick work known as the combustion chamber, passing the hot gases of cornbustion therefrom through flues formed in a certain other portion of the L brick work known as the checkerv chamber ork checker chambers and flues become sufficiently hot to then stop burn-V ing the mixture of gas'and air .andby means of suitable doors, valves, etc. to close the stove, thereby causing the stove tobecome art of the air conduit leading from the blowers to blast furnace. TheA air while passing through the stove absorbs the heat from the checker ,brick thaty form the lues of the checker chamber and also from they walls ofiv 30 the combustion chamber and becomes highly heated thereby. When the stove iscooled vH by the air, the air is then cut 0H from the stove and the stove is again heated as before. Usually three or four stoves are provided for a blast furnace, so that several stoves may be heating while one is being used to preheat the air for thefurnace.

Since they form no part of this invention it is unnecessary herein to describe in detail the Q40 various valves, cleaning doors, connections to cold blast mains and to hot blast mains and this invention is not concerned with the design of these parts,-but only with the material and manner of supporting the checkers. For *'45 the purpose of illustration we later herein' refer to that type of firel brick stove known as the center combustion two pass type, it being understood the invention is 'alsol applicable to side combustion lire brick type stoves with two or more passes' as wellas to when the brick' forming theseV UNITED STATES PATENT OFFICE l BLAST FURNACE noir BLAST siovn Application mea Decemberaz, issiaseriai No; 582,601;

the center combustion two pass .type of stove. l Heretofore, it'has been customary to supl port the brickforming the flues of the checker chambers by arches made of refractory material, but this method in view. of'modern re- 5 quirements is now unsatisfactory. The. tendency of modern hot blast stove construction is to obtain increased' capacities by kusing' greater stove heightsand diameters with higher air pressures and temperatures.

As a result it is difiicult to 4design refractory masonry arches of sufcient strength to carry the weight of the checker brick comprising the flues and at the same time leave sufficient passages therebetween for the gas'and air to 65 pass freely to and from the checker brick flues.

One ofthe obj ectsof'the 'present invention is to provide a new type of archfor-checker brick flue supports in blast furnace `hot blast l stoves. f i 70 Another object of the -present'invention is to improve the means of supporting checker brick forming fiues in hot blast stoves.

L vAnother object of the present invention-is to provide an; improved type ofhot blastv stove. f C

kThese and other objects will become ap.-v

plarertas the invention isA more-fully v'dis- A c ose yIn accordance with the-objects the pres- '80 y ent invention, I have designed an arched t-ype of checker brick support comprised of corrosion resistant metal, preferably of great structural strength, suchl as cast iron. lThis type of archedy support simplifies and vfacilitatesthe construction of hot blast stoves and provides means to increase'the output capacity ofthe stove.

Before` further disclosing the nature i and scope of the present invention reference f f `should be made to the accompanying drawings wherein- Fig. -1 is an elevationalv sectional View. of the lowerpart of atypical blast furnace hot bla-st stove, taken alongplanes Ge-Gr and 'H-H (lower and upper parts respectively) of Fig. 2 illustrating the application of the present invention; 1

' Fig. 2 is across-sectional view of the saine dividedinto staggeredplane sections A, B,L;.l 00

C, D, E and F to illustrate the building up of the :dues in the outer or checker chamber;

Fig. 3 is an enlarged plan view of a quarter section of Fig. 2 on plane C illustrating the method of setting up the arched supports of the present invention; and

Figs. 4; to 11 inclusive, are side elevational, top and end views of the arched checker brick supports of the present invention.V

Referring to the drawings, the blast furnace hot blast stove is comprised of an outer c lindrical steel casino 1 a refractoi brick e a y lining 2, a center cylindrical refractory brick wall 3 dividing the interior of the stove into two chambers l and 5, chamber 4 being open to convey products` of combustion from the bottom thereof to the top of chamber, and chamber 5 being filled with 'al plurality of checker brick flue openings identified by numeral 5a, the checker brick walls 6 forming the fines being supported on arched supports 7 in the manner shown. rlhe usual openings for the gas burner, the hot blast output, cold air input and for cleaning numbered 8, 9, 10 and 21 respectively, are provided but need not be describedin detail.

The arched support members 7, in accordance with the objects of the present invention, are comprised of corrosion resistant lmetal such as cast iron. Heretofore in the art checker brick have been supported by arches comprised of masonry and brickwork of various types and sizes. In addition to the disadvantages heretofore set forth masonry and brick arches are subject to deterioration during the operating life of a stove and require repeated rebuilding and replacement at each cleaning of the stove. VVhensuch a brick or masonry arch gives way the entire height of checker brick supported thereby is affected and often requires complete :replacement.

By the use of cast iron arched supports, in accordance with the present invention, va number of advantages are obtained which are not inherent in brick or masonry. Une decided advantage is greater strength to support the weight of checker brick, thereby giving an opportunity to increase the height of the fines. Another advantage is that the strength of the cast iron arched support permits tlie use of supports having a thickness substantially that of the width of the checker brick, thereby providing for an unrestricted flue channel from the top to the bottom of the checker chamber. rllhis greatly facilitates not only the flow of gas through the flues, but also the cleaning out of theflues. Another advantage in the use of arched supports comprised of cast iron, .is that the base of the supports may be widened out where they rest upon the supporting walls, thereby better distributing the load.

Another advantage is that for the same height of stove a relatively greater number Vthe same as those into the refractory brick of checker brick may be installed by using cast iron instead of masonry arches, due to the fact that a cast iron arch requires less height than masonry to obtain the same supporting strength. Cast iron having a lower specific heat ratio and more weight than lire brick, an increase in the rate of heat trans-` fer from the gas to the support and from Y the support to the cold air blast is obtained.

Time in constructing and time in repairing is also an important item in hot blast .stove construction and maintenance. By the use of cast iron 'arches a material saving in each is obtained. 3 i

The cast iron arched support of the present invention and the manner of utilizing the saine in a hot blast stove construction is fully set forth inthe figures of the drawing. Figs. 1, 2 and 3 show theA method of incorporating the supports in a stove and Figs. 4 to 11 inclusive, show various views of the supports.

Referring to Figsfi to 11 inclusive, the cast iron support element of the present iiivention is made in several structural modiii cations so that lthe same may be adapted to be positioned in dii'erent locations in the stove structure.v VOne modification is-shown in the side elevational, top and end plan views-of Figs. 1l, 5 and 6, whichis designed to be a main supporting arch for the flue checker brick and respective arched support members.` i Vrlhis type 4of support substantially comprisesan arch 11, a relatively wide horizontal plate flange 12, supported by the arch through an interconnecting body or rib portion 13 and Hanged feet portions 14 exh tendingreither side of the Varch 11 and rib portion 13.l Flanged ends -,l5v are provided to strengthen'thestructure.

vThe type illustrated in the sideV elevational i top and end plan views of' Figs. 7, 8 andvv9 respectively, is designed to be utilized as arched supports for the flue checker brick and comprise an arched body portion 16 ofsubstantially the saine thickness as the checker brickto be supported thereby, and flanged feet members 17 shown as .extending to one side only ofthe arched body portion.,

rllhe type of arched support member illustrate'd inside elevational end top plan views of Figs. 10 and l1, is the type utilizedto key in one quarter section of the checker brick supports with `another and is substantially shown in Figs. 7 8 and 9, flan-ged feet are cut ofi1 as illustrated at 18, at anangle. of substantially Ll5 degrees, to provide means to key in the supportingarches. As v'illustrated in Fig. 3, this type of arched support is of varying lengths depending upon its contemplated position .in theV supporting structure.

Referring to Fig. 3, the main supportin' arch identified therein as numeral 12 is builtfl walls 2 and 3 ina except that the manner as is illustrated with more particularity in Fig. l. rlhe flue brick arched supports (are thereafter bridged across the walls 2 and 3 in the manner illustrated, the main supporting arch l2 supporting the key arched supports identified as numeral 19 on one end in the manner shown.

Across the supports 7 and 19 is built up the checker brick flue structure 5a and 6 (Figs. land 2) substantially in the manner illustrated, the finished structure looking in cross-sect1on substantially as shown'in sec-l tion 2O of the cross-sectional view in Fig. 2. rlhe resulting structure thus obtained 1s characterized by being more rugged than the all masonry construction heretofore employed, and resistant to deterioration withl use. Cast iron is much more resistant to wear and tear and erosion under the operating conditions in a stove than is masonry. By the speciflic type of structure shown va free unrestricted tlowot air and gas through the flues is obtained, and or any spanning said walls in the lower part of the p disposed above and given height a plustove, supplemental metal arched members in a plane above the main supporting members Aand disposed obliquely thereto, some of said supplemental members being supported in part directly on said mainA supporting arch, and checker brick directly engaging the oblique supplemental arched members.

2.v A hot blast stove comprising inner and outer yconcentric circular walls delining respectively a combustion chamber and a checker chamber, a plurality of main radial metal members spanning the space between said inner and outer walls, each having an arched opening whose radial width is substantially equal to the distance between said inner and outer walls at the lower part of the stove, supplemental metallic arched members obliquely to the main members, and courses of checker brick supported directly on the supplemental arched members.

3. A hot blast stove outer circular walls,

comprising inner and a plurality of radial main supporting metal membershaving arch openings therein providing unobstructed passages therethrough 1n the lower part o the stove, supplementaly metal arches disposed obliquely to and located above the main supporting members, some of said supplemental arches having their inner ends resting on the main supporting members and their outer ends resting on the outer walls of the stove, and a plurality of courses of checker brick supported directly on the supplemental arches.

yIn witness whereof l have hereunto signed my name.

RAY @ABRI GAN. 

